Is there a specific reason why it should be CSV? Do you have a sample how this looks like? Where does that data come from?

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This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!

Even thought the OP didn't reply with additional information, I'm going to leave open as a (low priority) wish list.  The use main case I can think of is for income.  A regular paycheck may always have the same pay amount, but deductions for taxes and other expenses can change from one time period to another, and some users could find preparing a csv for import easier than either manually entering all the splits, or even duplicating a previous transaction and then altering some number of the splits.  I can also think of recording purchases from one store which include multiple categories, such as might be done by a mobile app which creates a csv file for import (recently discussed on the mailing list) for recording expenses.